Winter has died once before. In her past life, she didn't survive the extreme cold disaster. Reborn two months before the catastrophe, she divorced, emptied savings, bought an abandoned underground civil defense project, hoarding food, water, fuel, transforming it into a livable shelter. Everyone thought she was crazy. As temperature plummeted, the world froze into dead silence. This time, she must protect herself first, then decide—for whom that door will open.